Continuing to ride the train of success that AMD has had in 2004, AMD
is announcing today the completion of design work on their first dual-core
Opteron processor and the beginning of the tape-out process for that core.
While the first dual core CPUs won't be available until the middle of next
year at the earliest, AMD sees the beginning of the first dual core tapeout
as a pretty monumental step in their microprocessor evolution.

AMD is not providing much information about the new dual core CPUs other than
a low-resolution die shot and a roadmap; luckily we can derive a decent amount
of information from the die shot, so let's get to it.

First, here's a shot of a current generation 130nm Opteron die:

You can see that the majority of the functional units are on
the left of the die and the L2 cache and the 128-bit memory interface are both
on the right of the die. Now let's take a look at the finalized design for
the first 90nm dual core Opteron die:

As we mentioned earlier, the image is relatively low-res so you
can't see much detail in it but you should be able to see two distinct cores.
Although AMD isn't commenting on any of the details of the implementation,
it appears as if the first dual core Opterons are basically two Opterons connected
together on a single die - meaning each core has its own L2 cache. Here's a
good idea of what you're probably seeing above:

The DDR memory interface appears to wrap around both L2 caches,
meaning that it looks like both cores have their own 128-bit memory interface;
whether or not both memory controllers will be enabled is another thing, but
if this is true we have a number of implications to talk about.

If dual core Opterons do indeed have two memory controllers,
the pincount of dual core Opterons will go up significantly - it will also
make them incompatible with current sockets. AMD is all about maintaining socket
compatibility so it is quite possible that they could only leave half of the
memory controllers enabled, in order to offer Socket-940 dual core Opterons.
AMD isn't being very specific in terms of implementation details, but these
are just some of the options.

AMD did mention that they will eventually start referring to
Opteron server configurations according to the number of sockets, not CPUs,
the platform is capable of supporting. For example, a 1 socket Opteron server
could either be a 1-way or a 2-way configuration, depending on whether a single
or dual core Opteron is used.

AMD's Dual Core Roadmap

AMD also provided us with an updated roadmap, now including the
new Dual Core parts:

You can see that Egypt, Italy and Denmark are all dual core versions
of the 90nm Opteron 800, 200 and 100 series of processors. We'd assume that
they will be just dual core versions of their single core 90nm counterparts,
Athens, Troy and Venus (which if you will remember from our previous roadmaps
are basically smaller 90nm versions of the current Opterons, with no major
architectural changes). AMD will offer both full and low power versions of
their Opterons in dual core configurations, just like they do today.

The dual core Opterons are expected to hit in the middle of 2005,
then later in the 2nd half of 2005 we'll see the first dual core Athlon 64
FX. In 2006 we're expecting AMD to offer dual core versions of other CPUs in
their AMD64 lineup as well

We'll update you with more information about AMD's dual core
strategy as we receive it.